Incandescent lamp.



Patented July I, I902.

H. J. JAEGEB. INCANDESCENT LAMP.

(Application filed Aug. 13, 1901.)

(NoModeL) INVENTOR WITNESSES:

UNITED STATEsPA-TENT OFFI HERMAN J. JAEGER, OF NEIV YORK, N. Y.

INCANDE SCENT LAM P.

SPECIFICATION forming part of Letters Patent No. 703,791, dated July 1,1902.

Application filed August 13,1901- Serial No. 71,884. (No model.)

To all whom it may concern:

Be it known that L-HERMAN J. JAEGER, a citizen of the United States ofAmerica, and

a resident of New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Incandescent Lamps,of which the following is a specification.

My invention has reference to a novel construction of incandescentelectric lamps, and pertains particularly to that type of incandescentlamps known to the art as telephonelamps, which are at present generallyused in telephone-switchboards as the best form of annunciator.

The telephone-lamps heretofore employed are usually completely hidden inthe Wooden body of the switchboard, and a translucent button of largerdiameter than the lamp-body secured to a circular slitted brass holderis commonly inserted in the front portion of the switchboard in front ofthe lamp-top for the purpose of scattering the light, so that theincandescent filament is not visible, protecting thereby the eyes of theoperators from injury, which in the course of time get spoiled, owing tothe fact that the lamps are lighted and extinguished practically everyminute. This button adds a separate additional element to the outfit andmakes same more ex: pensive.

It is the object of my invention to provide a telephone-lamp whichdispenses entirely with this button, saving thereby its cost and thelabor of storing, handling, and mounting same. In order to accomplishthis desirable result and still protect the eyes of the operators frominjury, I have constructed a telephone-lamp in which a vacuum-chamber isprovided having a translucent top blown thereon, forming part of sameand being integral therewith.

My invention is illustrated in the accompanying drawings, in which--Figure l is a front elevation of the lamp embodying my invention. Fig. 2is a central vertical section of same. Fig. 3 shows the lamp in sideelevation without filament. Fig. 4 illustrates the lower portion of thevacuumchamber with the side seal; and Fig. 5 represents in modificationthe top of the vacuum-chamber, the translucent portion being tom end,and 0 represents the translucent top,

Which preferably is of half-globular shape, as shown in Figs. 1, 2,and3. This translucent top is blown onto the vacuum -chamber oftranslucent glass of any desired color, preferably of so-calledmilk-glass, but sometimes it is made of red, blue, or green glass, &c.The lamps, with differently colored translucent tops,may be mounted andarranged on the switchboard so that each color designates one section ofthe system or one small district. It is plainly understood from theabove that the translucent top is integral with the vacuum-chamber byvirtue of its manufacture and forms part of same. Its inner hollowsurface is exhausted with the chamber and to the same degree.

As shown-in Fig. 2, the translucent top is usually made thicker in glassthan the walls of the tubular chamber in order to insure a perfectscattering of the light, so that the in candescent filament is notvisible, protecting thus the eyes of the operators from injury. At andnear the walls of the tubular chamber the translucent top is graduallydecreasing in thickness. When mounted, it extends over the surface ofthe switchboard and is the only portion of the lamp which is visible tothe operator.

The support d is formed of two wires 6 e, which carry the filament f.Thesupport is strengthened by a bridge g. The lower ends of the wires 8e are made of" platinum wire where they pass through the side walls ofthe vacuum-chamber and form'a so-called side seal. Two terminals ofmetal it are provided on the sidesofthe tubular vacuumchamber. They aresoldered to the outside ends of the wires 6 e, and tightened on theoutside glass walls of the vacuum-chamber by a suitable cement, whichadheres both to the glass and metal. This protects the solderingpointand lead-in wires from injury. The terminals t' i extend below the glassbody of the lamp and are kept separate there in any con-- venient mannerby any suitable insulatingblock 70.

The filament in this lamp is of the small low voltage and amperagerequired by this kind of lamps.

Fig. 4 shows in detail the side seal. As is seen from this figure, thewires pass through the side walls of the tubular glass chamber. Thepoints where the wires pass through the glass walls are determined bythe length of the filament and its wire support. Sometimes they arepassing through near the bottom of the lamp, sometimes a little higherup, as shown in Fig. 4, and in some instances they may pass through theside walls in or near the central portion of the tubular chamber.

A modification of the translucent top is illustrated in Fig. 5, whereinthe translucent portion 0' is made to be even with the side walls of thetubular chamber. This form of lamp is convenient when it is desired tomount the lamp in the switchboard, so that the top of it is even withthe front surface of the board. In this waythe lamp is completelyprotected from accidental breakage while in operation.

Having thus described my invention, I

claim as new and desire to secure by Letters Patent 1. A telephone-lampcomprising a tubular glass vacuum-chamber, a thick half-globulartranslucent top joined thereto by the fusion of the glass and integraltherewith.

2. A telephone-lamp comprising a tubular glass vacuum-chamber, a thickhalf-globular translucent top integral therewith and decreasinggradually in thickness from its top center toward the walls of thetubular chamber.

3. A telephone-lamp comprising a tubular glass vacuum-chamber, a thickhalf-globular translucent top joined thereto by the fusion of the glassand decreasing gradually in thickness from the top toward the walls ofthe tubular chamber, and a bottom vacuum-seal.

Signed at New York, N. Y., this 10th day of August, 1901.

HERMAN J. JAEGER.

Witnesses:

L. K. BOHM, JAMES J. AS'IARITO.

